Vulnerability in Hubspot Jinjava

CVE-2025-59340

jinjava is a Java-based template engine based on django template syntax, adapted to render jinja templates. Priori to 2.8.1, by using mapper.getTypeFactory().constructFromCanonical(), it is possible to instruct the underlying ObjectMapper to deserialize attacker-controlled input into arbitrary classes. This enables the creation of semi-arbitrary class instances without directly invoking restricted methods or class literals. As a result, an attacker can escape the sandbox and instantiate classes such as java.net.URL, opening up the ability to access local files and URLs(e.g., file:///etc/passwd). With further chaining, this primitive can potentially lead to remote code execution (RCE). This vulnerability is fixed in 2.8.1.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.021 (81.1th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 81st percentile — 81.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-59340: held from 0.021 to 0.021.

EPSS over last 30 days · oldest: 0.021 · newest: 0.021 · change: +0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-59340?
CVE-2025-59340 is a critical-severity vulnerability in Hubspot Jinjava, classified under Improper Neutralization of Special Elements Used in a Template Engine. CVSS score: 9.8/10. Published 2025-09-17.
How severe is CVE-2025-59340?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2025-59340 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.